The invention pertains to improvements to machinery to wind capacitors, and particularly those capacitors which incorporate more than one capacitor in the same winding. Machines have heretofore been designed to wind capacitors of this type. In particular, one prior art machine has met considerable commercial success. That machine, the semi-automatic Hilton Capacitor Winding Machine, manufactured by Hilton Industries, Inc., Glen Falls, New York, provided a partial answer to the industry's need for a capacitor winding machine. Specifically, this machine incorporated means for supplying the necessary dielectric layers, foil, and terminals to an arbor which was winding the capacitor. The machine automatically fed the proper lengths of foil to form the various capacitor electrode and, at approximately the proper time, fed foils with metallic tabs which formed the terminals of the capacitor.
Unfortunately, this machine, despite some automatic operations, required the full-time attendance of an operator. Among the functions that this operator had to perform were threading the severed ends of the dielectric layers onto the arbor to allow the machine to wind another capacitor, sealing the ends of the wound capacitor to prevent it from unraveling, and removing the wound capacitor from the arbor. The operator also had to reorient the capacitor tabs so that they assumed the proper angular relationship, and, when the finished capacitors tended to collapse, manually insert a structural reinforcement at the beginning of the winding of the succeeding capacitors.
Beside the cost of the labor necessitated by this machine, manual operations are subject to human error. Therefore, it has been a long-standing goal in the capacitor winding industry to reduce the amount of manual labor needed to produce wound capacitors.
Prior attempts to design an automatic capacitor winding machine have not met with commercial success. These attempts have encountered numerous problems.
One major problem is automatically removing the wound capacitor from the winding arbor without telescoping of the capacitor, i.e. the inner windings of the capacitor body pulling out of and extending past the main body of the capacitor. This problem seems to be caused by the friction between the innermost winding and the arbor, which tends to keep the innermost winding on the arbor. Unfortunately, normal lubrication techniques (oil, grease) cannot be used to reduce the friction since they would degrade the capacitor. Attempts to strip the capacitor off the arbor by close tolerance strippers have previously failed because of the wear suffered by these parts, destroying the tolerances.
Another problem left unsolved by the prior art machines is automatically preventing the collapse of the capacitor when stripped off the arbor. In the semi-automatic machines, structural inserts were manually fed into the capacitor. However, in automating the machine, prior attempts have not been successful in designing an automatic structural insert device.
Another problem is to insert the tabs (terminals) of the capacitor in the proper angular relation. This requires that the machine know the exact angular position of the first tab, so that latter tabs can be properly inserted. Prior art machines attempted to solve this problem by counting arbor rotations. However, this system has proved expensive and unreliable.
Moreover, most prior art attempts to design an automatic capacitor winding machine have involved designing a machine from scratch. This has resulted in expensive, complicated, and unreliable machines. The present invention can be used to modify prior art machines, and in fact, such a modification is the preferred embodiment of the present invention.
Consequently, it is an object of the present invention to attain an automatic capacitor winding machine, preferably in a form that permits modification of prior art semi-automatic machines.
It is also an object of the invention to obtain a mechanism to strip capacitors off arbors without capacitor telescoping and with minimum stripper wear.
It is also an object of this invention to obtain a machine that knows the position of a tab inserted into a capacitor without counting arbor rotations.
Another object of this invention is to obtain an automatic structural insert means, preferably constructed to fit within the confines of the prior art semi-automatic machines.
The present invention has met the above and other objects. Although the features of the present invention are embodied in a specific automatic capacitor winding machine, from the below description, one skilled in the art will be able to embody these features into other environments, not limited to capacitor winding machines.